Battle against wasps to ramp up in south

War will be declared on wasps in the Craigieburn Range as part of the largest operation of its kind carried out in New Zealand.

The first stage of a control operation is planned for early next year organised by the Waimakariri Environment and Recreation Committee (WERC) in the upper Waimakariri catchment.

Project organiser Penny Wright said invasive wasps were probably the most widespread and damaging invertebrate pests in the country.

"They are particularly bad in honeydew beech forests."

Researchers estimated that at this time of the year, the total weight of wasps could be as high as the combined weight of birds, rodents and stoats in the same area of forest.

Dr Mark Floyd, an occupational health adviser to the Department of Conservation, said that the last summer season was the worst for many years in recorded wasp and bee stings for DOC employees. Allergic reactions to insect stings are estimated to occur in about 3 per cent of adults, but almost 50 per cent of fatal reactions occur in people with no allergic history.

A survey of bird numbers will be carried out both before and after the Craigieburn control.

This is because wasps have a major impact on invertebrate populations and honeydew availability. They are implicated in declining numbers of birds which depend on these food sources - rifleman, grey warbler, tomtit, bellbird and kaka, WERC chairman, Peter Dawkings said.

Wasps have even been recorded to consume recently hatched chicks in the nests of small birds.

The Craigieburn Wasp Control Project will be the largest such operation ever carried out in New Zealand, and will rely on teams of volunteers to be completed.

The Press